apr1cot

Спасибо Дмитрий за подсказку. В итоге сделал вот так:

Вместо трёх таблиц создал одну, и сделал выборку с помощью groupBy

$postbacks = DB::table('postbacks as p')
            ->select(
                DB::raw('DATE(p.created_at) as date'),
                'u.name as user_name',
                'c.name as campaign_name',
                'c.domain',
                'pr.name as provider_name',
                'pr.commission',
                DB::raw('SUM(p.income) AS t_income'),
                DB::raw('SUM(p.cost) AS t_cost')
            )
            ->join('campaigns as c', 'p.campaign_id', '=', 'c.id')
            ->join('providers as pr', 'c.provider_id', '=', 'pr.id')
            ->join('users as u', 'c.user_id', '=', 'u.id')
            ->whereBetween('p.created_at', ['2023-08-15', '2023-08-17'])
            ->where('c.user_id', 1)
            ->groupBy(DB::raw('DATE(p.created_at)'), 'c.id')
            ->orderBy('date', 'ASC')
            ->get();

Решение моей проблемы, для тех, кто столкнется с такой же проблемой.

public class BrandHolder extends RecyclerView.ViewHolder implements View.OnClickListener{

    public String    id;
    public CardView  cardBrand;
    public TextView  txtTitle;

    public BrandHolder(View itemView) {
        super(itemView);

        itemView.setOnClickListener(this);

        //String itView = String.valueOf(itemView);

        cardBrand   = (CardView)  itemView.findViewById(R.id.cardBrand);
        txtTitle    = (TextView)  itemView.findViewById(R.id.txtTitle);
    }

    @Override
    public void onClick(View v) {
        Log.d("ITEM", String.valueOf(this.id));
        Snackbar.make(cardBrand, "onClick at position : " + getLayoutPosition(), Snackbar.LENGTH_LONG).show();
    }
}